The present invention relates to a system for controlling an ignition device for vehicles, and more particularly to a system for controlling movement of a key operated movable member of an engine ignition device such that the key operated movable member will not return once the key operated movable member has moved beyond a predetermined position until the vehicle assumes a predetermined condition, even though such return movement is permitted if a manual release member is operated after the vehicle has attained the predetermined condition.
The present invention is applied to a motor vehicle equipped with an engine ignition device operable by a key operated member and a parking mechanism. The parking mechanism is operated when a manual shift lever is placed at a "P" (Parking) position in a motor vehicle with an automatic transmission or when a manual parking brake lever is pulled in a motor vehicle with a manual transmission. The vehicle therefore assumes a predetermined condition where it is forced to stay at a halt and thus it will not move.
Usually, the engine ignition device includes an ignition switch incorporated in a locking device for a vehicle steering mechanism and is operable by a key operated rotatable lock cylinder disposed in a stationary cylinder housing. When a proper key is inserted in a key slot formed in the lock cylinder, the lock cylinder is rotatable from a "LOCK" position to an "ON" position beyond an "ACC" position, and then to a "START" position. The "ACC" position, "ON" position and "START" position correspond to respective operating positions, namely "ACC", "ON" and "START", of the ignition switch. The locking device carries in a housing a locking bolt, such that when it is suitably mounted on a motor vehicle steering column, the bolt may extend into the steering column to lock a steering shaft extending through the steering column. In order to prevent inadvertent rotation of the key operated lock cylinder to the "LOCK" position, the locking device usually comprises a mechanism for automatically blocking the key operated lock cylinder against return movement to the "LOCK" position once the key operated lock cylinder has moved beyond the predetermined position. The blocking mechanism includes a blocking pawl which is movable to a blocking position by means of a rotary cam rotatable with the key operated lock cylinder and retained in the blocking position once the key operated lock cylinder has moved beyond the predetermined position from the "LOCK" position. A manual button is disposed in the vicinity of the hole which can be depressed when the key operated lock cylinder returns to an "OFF" position to move the blocking pawl from its blocking position to a released position. Thus, the key operated lock cylinder can be returned to the "LOCK" position if the manual button is depressed and the key can be removed from the key operated lock cylinder when and only when the key operated lock cylinder has returned to the "LOCK" position.
Drivers' behavior differs from one person to another. For instance a driver may leave the vehicle with the shift lever of the automatic transmission placed at "R" (Reverse) range position rather than returning it to the "P" (Parking) position when the vehicle is parked on a slope. In this case, if he or another person tries to start the engine by inserting the key into the lock cylinder and rotating it to the "START" position, the engine will not start running until the shift lever is returned to the "P" or "N" (Neutral) position.
An object of the present invention is to eliminate this cumbersome operation which would otherwise be required upon re-starting the engine subsequently.
More particularly, an object of the present invention is to provide a system for controlling an ignition device such that a driver of a motor vehicle is always motivated to force the vehicle to stay at a halt before removing a key from a lock cylinder so as to eliminate the above-mentioned cumbersome operation which would otherwise be required upon re-starting the engine subsequently.